feat: add --debug tracing to hendi_ctrl_app.py, document v1.16 fix

HendiCtrl.cmd() previously raised a bare "Communication error" for any
non-OK response, discarding the firmware's actual reply. It now
includes the raw echo/answer bytes, and --debug prints every
request/response. Using this, the rejected R1 during lockout turned
out to be an explicit "ERR:Invalid state" reply, not a timeout.

Also flashed and retested v1.16: plain reconnect (no --reset) now
recovers from the lockout reliably (4/4 trials), fixing the
intermittent behavior seen on v1.15.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GpePKZiEZWbGo9HrfuML6U

components/actor/hendiCtrl.py

@@ -10,7 +10,8 @@ class HendiException(Exception):
 	pass
 
 class HendiCtrl:
-	def __init__(self, port, speed):
+	def __init__(self, port, speed, debug=False):
+		self.debug = debug
 		self.ser = serial.Serial(port, speed)
 		try:
 			self.ser.open()
@@ -102,6 +103,8 @@ class HendiCtrl:
 	def __write(self, s):
 		self.ser.flushInput()
 		data = s.encode()
+		if self.debug:
+			print(f"HendiCtrl: -> {data!r}")
 		self.ser.write(data + b'\r')
 
 	def __read(self):
@@ -109,21 +112,24 @@ class HendiCtrl:
 		echo = self.ser.readline()
 
 		# Read answer line
-		answer = self.ser.readline().decode('utf-8').replace('\r', '').replace('\n', '')
+		answer_raw = self.ser.readline()
+		if self.debug:
+			print(f"HendiCtrl: <- echo={echo!r} answer={answer_raw!r}")
+		answer = answer_raw.decode('utf-8').replace('\r', '').replace('\n', '')
 		if ':' in answer:
 			result = answer.split(':')
 		else:
 			result = answer
 
-		return result
+		return result, echo, answer_raw
 
 	def cmd(self, req):
 		self.__write(req)
-		rsp = self.__read()
+		rsp, echo, answer_raw = self.__read()
 		if len(rsp) == 0:
-			raise HendiException(f"Communication error")
+			raise HendiException(f"Communication error: req={req!r} echo={echo!r} answer={answer_raw!r}")
 		if "OK" not in rsp[0]:
-			raise HendiException(f"Communication error")
+			raise HendiException(f"Communication error: req={req!r} echo={echo!r} answer={answer_raw!r}")
 
 		return rsp[1]